805 A Simple Technique to Create Partial-Thickness Wounds and Harvest Split-Thickness Skin Grafts in Rat Models

Abstract Introduction Developing reliable methods that can generate partial-thickness (PT) wounds of consistent sizes in rats would be a valuable tool for testing and developing novel strategies for wound healing. The process of harvesting a split-thickness skin graft (STSG), which also creates a cutaneous wound, in rats is difficult due to their skin laxity and small size. Current methods in the literature can be time-consuming, require additional supplies, or cannot be performed by a single operator. We propose a novel one-person solution that uses a circular dermatome. We further validate this technique’s reliability in creating STSGs/PT wounds of consistent thickness in rats. Methods Technique: Donor site fur was trimmed with electric clippers. The rat was firmly grasped by the non-dominant hand so as to ensure that the donor site skin was taut. Lubricating gel was applied to the donor site. The circular dermatome, set to the desired depth, was held in the dominant hand. Downward, constant pressure was applied with the circular dermatome, with the blade first making contact with the planned donor site's rostral end. Maintaining pressure, the dermatome was pulled caudally until the desired STSG donor site size was reached. Validation: To assess this method's reliability in creating STSGs of consistent thickness, skin grafts (with the device set to 0.001 in.) were harvested from the left bony, left non-bony, right bony, and right non-bony dorsal thoraces on two rats for eight total samples. Samples were fixed in 4% paraformaldehyde, cryosectioned, stained with hematoxylin/eosin, and imaged at 20X. Using an image processing program, 40 thickness measurements (in.) were taken along each sample length. Coefficients of variation (CV) were calculated and compared between samples. CV thresholds for levels of reliability were defined as the following: CV< 10% (very good), CV=10-20% (good), CV=20-30% (fair), and CV>30% (poor). Results All four grafts harvested from bony thoraces had CV values between 10-20%. Three of the four grafts harvested from non-bony thoraces had CV values between 10-20% and one had a CV< 10%. Among the grafts with CV values between 10-20%, one graft harvested at a bony site had a CV< 15%, while three grafts harvested at non-bony sites had a CV< 15%. The average time required to harvest one graft was five minutes, with an average of five seconds for active circular dermatome use. Conclusions This simple technique can be employed to harvest STSGs and create PT wounds in rat models with overall good thickness consistency. Using this device on non-bony donor sites may be preferred for maximizing intra-graft thickness consistency. This proof-of-concept study requires further validation to optimize STSG donor/PT wound site selection. Applicability of Research to Practice This single technique is suitable for both wound healing and STSG studies, allowing researchers to optimize efficiency without compromising reliability.

Introduction: Developing reliable methods that can generate partial-thickness (PT) wounds of consistent sizes in rats would be a valuable tool for testing and developing novel strategies for wound healing.The process of harvesting a split-thickness skin graft (STSG), which also creates a cutaneous wound, in rats is difficult due to their skin laxity and small size.Current methods in the literature can be time-consuming, require additional supplies, or cannot be performed by a single operator.We propose a novel one-person solution that uses a circular dermatome.We further validate this technique's reliability in creating STSGs/PT wounds of consistent thickness in rats.Methods: Technique: Donor site fur was trimmed with electric clippers.The rat was firmly grasped by the nondominant hand so as to ensure that the donor site skin was taut.Lubricating gel was applied to the donor site.The circular dermatome, set to the desired depth, was held in the dominant hand.Downward, constant pressure was applied with the circular dermatome, with the blade first making contact with the planned donor site's rostral end.Maintaining pressure, the dermatome was pulled caudally until the desired STSG donor site size was reached.
Validation: To assess this method's reliability in creating STSGs of consistent thickness, skin grafts (with the device set to 0.001 in.) were harvested from the left bony, left nonbony, right bony, and right non-bony dorsal thoraces on two rats for eight total samples.Samples were fixed in 4% paraformaldehyde, cryosectioned, stained with hematoxylin/eosin, and imaged at 20X.Using an image processing program, 40 thickness measurements (in.) were taken along each sample length.Coefficients of variation (CV) were calculated and compared between samples.CV thresholds for levels of reliability were defined as the following: CV< 10% (very good), CV=10-20% (good), CV=20-30% (fair), and CV>30% (poor).Results: All four grafts harvested from bony thoraces had CV values between 10-20%.Three of the four grafts harvested from non-bony thoraces had CV values between 10-20% and one had a CV< 10%.Among the grafts with CV values between 10-20%, one graft harvested at a bony site had a CV< 15%, while three grafts harvested at non-bony sites had a CV< 15%.A total of 577 injury sites were evaluated.The fail rate for PBM+STSG+ASCS, STSG+ASCS, ASCS+ non-donor site, and ASCS on donor site was (2.9%, 0.4%, 0.0%, 0.5%), respectively.No complications were reported with ASCS on donor sites.The percent fail of STSG's without ASCS was 6.6% and reduced to 0.4% when used in combination with STSG+ASCS.

Conclusions:
The findings of this study data demonstrate the successful application of ASCS even in the presence of infection on burn and complex wounds used alone or in conjunction with PBM.The results support the off-label use of ASCS on donor sites.

Applicability of Research to Practice:
This study demonstrates the effectiveness of ASCS on wounds as well as the use on donor sites.This study adds to the growing literature evaluating the use of ASCS on burn wounds.

citation ID: irae036.346 806 Autologous Skin Cell Suspension Demonstrates Successful Outcomes in the Treatment of Burn and Wound Sites
The average time required to harvest one graft was five minutes, with an average of five seconds for active circular dermatome use.Conclusions: This simple technique can be employed to harvest STSGs and create PT wounds in rat models with overall good thickness consistency.Using this device on nonbony donor sites may be preferred for maximizing intra-graft thickness consistency.This proof-of-concept study requires further validation to optimize STSG donor/PT wound site selection.Applicability of Research to Practice: This single technique is suitable for both wound healing and STSG studies, allowing researchers to optimize efficiency without compromising reliability.Literature reports on the use of ASCS but there is a paucity of data describing the application of ASCS with temporal dermal substitutes and donor sites.The purpose of this study is to evaluate complex wound sites due to burns and other etiologies treated with ASCS solely or in combination with wound care applications.Also, a review of ASCS applied over donor sites is reported.We hypothesize the application of ASCS on complex wounds, burns and off-label usage on donor sites to demonstrate acceptable outcomes.